What it does: 

Adding sounds like the shuddering TARDIS sound when it aborts rematerialisation due to obstruction, like when the green text pops up. 

Also add the Cloister bell when the tardis fluid links/fuel is low.

How it benefits: 

It adds to the immersion of the game.  Adding the sounds makes the TARDIS(s) feel more like what's in the show.

Why it would be cool: 

The TARDIS has many sounds and that's partially what makes it so cool.